Immediately after the Fort Hood rampage last week, many were quick to label the shooter as a soldier with post-traumatic stress disorder (PTSD).

But to others – soldiers and mental health experts alike – this snap judgment stigmatizes combat veterans diagnosed with this signature ailment of wars in Iraq and Afghanistan, and it’s a simplified and short-hand reading of a far more complicated issue.

Medal of Honor recipient Sgt. Dakota Meyer, USMC, who struggled with post-traumatic stress after returning from Afghanistan and who once contemplated suicide, says, “Going out and shooting your own friends, your own people, that’s not PTSD…. It’s close to psychotic.”

The shooter at Fort Hood was Sgt. Ivan Lopez, who shot and killed three fellow soldiers, wounding 16 others before taking his own life when confronted by a military police officer. Officers at the sprawling US Army base near Killeen, Texas, say Sgt. Lopez appears to have been in a dispute with others in his unit over an application for time off.

Although he was not engaged in combat during a four-month deployment to Iraq in 2011 – apparently had not been in any stressful traumatic circumstances, according to his service record – Lopez was being treated for anxiety and depression, and he was in the process of being diagnosed for PTSD. He also had reported the effects of traumatic brain injury (TBI) – the other signature wound of recent wars, associated with roadside bomb attacks – although, again, there was no indication of such an injury in Lopez’s record in Iraq.

In any case, says New York psychiatrist Prakash Masand, “This is an extremely rare incident and shouldn’t be cause for stigmatizing veterans or others with mental illness.”

“The majority of veterans, with or without PTSD, can be model citizens, employees and family members,” Dr. Masand says via e-mail.

In fact, as Monitor Pentagon correspondent Anna Mulrine, points out, many veterans and senior military officers consider “PTSD” to be a misnomer with “post-traumatic stress” – the understandable reaction to traumatic incidents, which is not a “disorder” – the more accurate description.

While the US Department of Veterans Affairs (VA) estimates that as many as 20 percent of Iraq and Afghanistan vets experience post-traumatic stress – the figure is 30 percent for Vietnam War veterans – Dr. Masand says it’s important to note that “more than three-quarters of individuals in the armed forces who have a psychiatric illness, had it prior to enlistment.”

Meanwhile, as investigators at Fort Hood, and the Army generally, try to understand how this latest episode of on-base violence might have been predicted or prevented, the debate over gun control and mental health continues.

The default position for the National Rifle Association (NRA) and other gun advocates – as it was after the Sandy Hook Elementary School massacre in Newtown, Conn., which killed 20 first-graders and six adult educators in a hail of semi-automatic weapon fire – is that more guns in public places can make society safer.

The .45 caliber Smith & Wesson semi-automatic handgun that Lopez used in the attack was purchased legally at “Guns Galore” near Fort Hood. But neither he – nor any other soldier except for military police officers – was allowed to carry it on base, concealed or openly.

US Rep. Mike McCaul (R) of Texas, chairman of the Homeland Security Committee, is pushing legislation to allow members of the military to carry concealed weapons on base.

"We should be looking at the idea of senior leadership at these bases, give them the ability to carry a weapon,” Rep. McCaul said on "Fox News Sunday." “They defend us overseas and defend our freedom abroad, so the idea that they are defenseless when they come on our home bases, I think, Congress should be looking at that and having a discussion with the bases about what would be the best policy.”

It’s not an idea embraced by many senior military officers or civilians.

“I’m not one – as someone who has been on many, many bases and posts – that would argue for arming anybody who is on base,” retired Adm. Michael Mullen, former chairman of the Joint Chiefs of Staff, said on NBC's "Meet the Press." “I think that actually invites much more difficult challenges.”

“Certainly we have to do everything we can to protect everybody that’s on base," Adm. Mullen said. “I’m sure this incident will cause Secretary [of Defense Chuck] Hagel to review those procedures. But I’d be much more in the camp of fixing it that way and focusing on the individuals rather than routinely allowing arms on any military base in the country.”